Prior-art apparatuses for extracting the energy from masses of moving or flowing fluids generally utilize the immersion of one or more blades in a moving fluid. The blades are coupled to a rotating shaft. The extraction of the energy in the flowing fluid is attempted to be optimized by proper design and orientation of the blades.
The portion of the energy extracted by the blades from the moving fluid is delivered by causing a shaft coupled to the blades to rotate with torque that is usually some fraction of the energy brought to the scene by the moving fluid, yet sufficient to supply some energy to the load coupled to the shaft, such as a pump, generator, or . . . . Examples of such prior-art energy extraction devices are wind turbines, water turbines, steam turbines, paddle wheels, and the like.
While such prior-art extracters have a long and successful history, they are lacking in efficiency in some cases, and convenience in others. For example, a well-known Betz's law, states that a wind turbine can in theory extract only a maximum of 59% of the energy of the wind incident on the turbine. In practice the extracted energy never exceeds 70-80% of the theoretical Betz limit; thus the best one can expect from running wind turbines is between 41-47% of the energy present. Wind turbines, like solar extracters, are intermittent, and most can actually extract energy only when the wind speed is between about 2.5 to 25 meters/second (m/s). The seasoned practitioners in the art—when pressed—admit that overall delivery expectancy from all now visible such devices will not be more than about 30% of the energy actually available for our taking from the of moving fluids incident to them. That most discouraging conviction includes tidal sea movements, and power from “hydro” origins is barely included any more in the “knowledgeable” projections of energy sources.
The newest attempts to extract energy from the seas are the various “wave machines”; each uses the vertical lift of the sea wave as the input, sometimes to drive a generator directly, or to do so through various forms hydraulic or pneumatic devices.
Because of the meager yield from each device, they are often grouped in chains or an array of units packaged into one container.
PR for the whole field (an essential tool in fund raising) has become frantic, and truth is very difficult to determine. The actual results of the various attempts are so far from the loudly proclaimed ones, that the June 2010 issue of POPULAR MECHANICS, in its excellent review of the renewables situation, takes on as “Myth No. 5—TIDAL POWER IS A LOST CAUSE” on page 74.
No environmental group has as yet awaken (with horror) to what our shores would look like when a serious effort to produce some of our energy needs from the various wave devices is attempted—and endless bouy's and hinged chains of large metal boxes would have scarred the near seas. Scotland has declared itself the “Saudi Arabia of Marine Power”, and commendable efforts to sort out the field are in progress there. They list (via www.bwea.com/marine Note: “bwea” is now known as “RENEWABLESUK”), the “three main methods” for extracting energy from tidal or otherwise “currents”, as being “Cross Flow Turbines” “Reciprocating Hydrofoils”, and “Axial Turbines”. Popular Mechanics states than an “array of Axial Turbines (at least 3?) “operated for more than 9000 hours” in year 2008, in New York's East River, “delivering 70,000 KWHrs”; if that is correct, than each Axial Turbine produced appx 70000/(3×9000)=2.6 kwh . . . . The “output” of such turbine is shown in an ad also pictured there as 35 kw. British Petroleum—now famous for another most unfortunate reason—has not too long ago been promoting its initials, BP, as “Beyond Petroleum . . . . Then, perhaps not surprisingly, the hard headed oil men seemed to move away, in a virtual abandonment, from the hope that other than fossil fuels can possibly produce even a significant portion of the world's annual 15,406 Tera Watt Hours electric power use . . . (2004 CIA World Book) Note: 1 TWhr=1,000,000,000,000 Watt Hrs.
Yet many knowledgeable sources mirror the 1995 Report to the Office of Science and Technology of the British Commons (by the Marine Foresight Panel), which states that if only 0.01% of the seas energy were captured, it would equal to 5 times the entire world's need for energy . . . .
The movement of masses of fluids, especially in the seas alone, CAN yield all the energy we need. This application hopes to start a movement toward far greater, more serious, energy quantity extraction from each installation, and perhaps accelerate the unavoidably coming conclusion: “YES we CAN! become less and less fossil fuels dependent, in a major way, starting NOW . . . .